How do we pass parameters to the server?

Below are the two ways of passing data to server. The first one shows by using GET and the second by POST.xmlHttpObj.open("GET","http://" + location.host + "/XmlHttpExample1/ WebForm1.aspx?value=123", true);xmlHttpObj.open("POST","http://" + location.host + "/XmlHttpExample1/ WebForm1.aspx?value=123", true);